Hello,
out of the blue my external HD does not recognize the first out of 3 Partitions anymore.
Partition G shows as unformatted, H and J are fine.

Analyzing with Test Disk showed a wrong number of heads per cylinder.
After changing that and analyzing again the partition in question now shows as extended LBA.
I tried changing it to NTSC, but that did not help.

How can I get the partition to be readable again? Any solution to access the data is welcome.